This invention relates to wastewater treatment and, particularly, to the removal of a plurality of heavy metals and radioactive isotopes from wastewater to produce a sludge containing the contaminants. Many industries produce wastewaters containing heavy metals and/or radioactive material. Environmental laws regulate the discharge of wastewater containing heavy metals and/or radioactive isotopes. Wastewater containing heavy metals are generated by a wide variety of industries, such as metal finishing, automobile manufacturing, electronics manufacturing, textile industry and others. Wastewaters containing radioactive isotopes are generated by the mining of ore, refining of ore, milling, wash-downs, fuel preparation, cooling waters, as well as hospitals and research facilities. A combination of heavy metals and radioactive material is often present in run-off ponds at mining areas.
The problem is the considerable volume of wastewater containing heavy metals and/or radioactive material throughout the world and the lack of effective and economical treatment and, more particularly, the removal of heavy metals and the removal of radioactive isotopes from the wastewater, separately or in combination.
The present invention obviates these inherent problems by providing an effective wastewater treatment method capable of removing a plurality of diverse heavy metals and radioactive isotopes from wastewater and fixing or adsorbing same onto a usually stable sludge, thus rendering the water free of heavy metals and radioactive material. These waters can then be safely discharged or, in many cases, recycled, which results in additional savings to industry and in the protection of natural resources, the public health and the environment.